Contactor with antiwelding device.



M. K. KJOLSETH.

councroa WITH ANTIWELDING DEVICE.

APPLICATION FILED MAR. 31. 19H.

1,176,569. Patented Mar. 21, 1916.

Witnesses: Inventor:

W AQ athIas K. KJ lseth. a

UNITED STATES PATENT OFFICE.

MATHIAS K. 'KJOLSETH, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CONTACTOR WITH ANTIWELDING DEVICE.

Application filed March 31, 1914.

To all whom it may concern r Be it known that I. NIATHIAS K. KJoL- SETH, a subject of the King of Norway, residing at Schenectady. in the county of Schenectady, State of New York, have in vented certain new and useful Improvements in Contactors with Antiwelding Devices, of which the following is a specification.

My invention relates to electromagnetic switches, and has for its object the provision of an improved device of this character which is compact and efiicient in operation, and in which it isimpossible for the contacts to stick or freeze together under the most trying conditions of service.

In operating switches of the above character, and particularly in the operation of such as are used for the control of electric motors which require frequent operation and which must carry heavy currents, the are formed between the contacts sometimes causes them to weld, and stick together. This action may be brought about by an instantaneous energization of the magnetizing coil so as to bring the contacts lightly together, but without forcing them home into firm engagement. In switches of this character. where the contacts slide or roll upon each other. any slight weld will be overcome when the contacts are brought into firm engagement. hen, however the contacts are brought together to touch each other only lightly or as technically termed in. the art, when they kiss each other, a weld may form which is sufficient to keep the contacts closed against any tendency of gravity to open the switch.

My invention has for its object the provision of improved means for preventing the contacts from sticking together in the manner above indicated and is an improvement over the invention covered by the pat ent to John Eaton, #1,16(3,339, assigned to the same assignee as the present application.

For a fuller understanding of my invention reference may be had to the accompanying drawing, in which the figure is a side "iew partially in section of a switch embodying my invention.

Referring to the drawing, 1 is a frame to which are secured brackets 2 and 3. An electromagnet 4 carrying the usual magnetizing winding is mounted on the bracket This magnet is provided with a cooperating Specification of Letters Patent.

Patented Mar. 21. 1916.

Serial No. 828,544.

armature 5 pivoted on the bracket 2 at G. On the armature is pivotally mounted a member 7. preferably in the form of a twoarmed lever, one arm 7 of which carries a movable contact 8 which is adapted to engage a fixed contact 9 mounted on the bracket The other end 7 of the lever ex tends adjacent the armature and is biased away from the armature by a spring 10 mounted between the arm 7" and a movable member, preferably in the form of a plunger 11 provided with a head 12 carried by the armature against which the inner end of the spring 10 is seated. I have here shown the plunger as passing through the armature and adapted to engage the core of the magnet l, and the parts are so arranged that the plunger engages the end of the magnet just before the movable contact 8 is brought into engagement with the fixed contact 9. The outward movement of the arm 7 of the lever T is limited by a stop which I have here shown as consisting of a screw 13. against the head of which the end of the arm 7* normally rests.

\Vhen the magnet 1 is deenergized, the head 12 of the plunger 11 is seated against the armature 5 and the inner end of the plunger 11 extends beyond the opposite face of the armature so that the plunger will engage the end of the magnet when the same is energized. \Vhen the magnet is deener gized, the extreme end of the arm 7* of the lever T is forced against the head of the screw 13 by the spring 10. Xow when the magnet 1 is energized, the armature is attracted and the inner end of the plunger 11 engages the core of the magnet just prior to the engagement of the contact 8 with the contact 9. This action places the spring 10 under compression and the armature 5 with contact 8 upon it is thus biased to move away from the contact 9 during the entire time that it is in engagement therewith, and the force exerted by the spring is sutlicient to separate the contacts, even when a slight weld has been. formed in the manner hitherto indicated.

IVhile I have described my invention as embodied in concrete form and as operating in a specific manner in accordance with the provisions of the patent statute s, it should be understood that I do not limit my invention thereto, since various modifications thereof will suggest themselves to those skilled in the art without departing from "hich is set forth in the annexed claims.

\Vhat I claim as new and desire to secure by Letters Patent of the United States, is

1. An electromagnetically actuated switch, comprising a magnetizing winding, an armature therefor, a fixed contact, a member pivoted to said armature carrying a contact arranged to engage the fixed contact, a resilient member interposed between the armature and the pivoted member, and means comprising an element mounted upon the armature and movable with reference thereto for bringing said resilient member into a condition to bias the movable contact away from the fixed contact before the contacts engage.

2. An electromagnetically actuated switch, comprising a magnetizing winding, an armature'therefor, a fixed contact, a member pivoted to said armature carrying a contact arranged to, engage the fixed contact, a spring engaging the pivoted member, and means comprising a plunger mounted on the armature and arranged to engage the end ofthe magnet and place the spring under compression prior to the engagement of the contacts, whereby the movable contact is biased away from the fixed contact before the contacts engage.

3. An electromagnetically actuated switch, comprising a magnetizing winding, an arma ture therefor, a fixed contact, an elbow lever pivoted to said armature, one arm of the lever-carrying a contact arranged to engage the fixed contact, the other arm extending adjacent the armature, a stop for limiting the movement of the second arm of the lever away from the armature, a resilient member interposed between the armature and thes'econd arm of the lever and means for bringing said resilient member into a condition to bias the movable contact away from the stationary one before the contacts engage.

In witness whereof, I have hereunto set my hand this 30th day of March, 1914.

MATHIAS K. KJOLSETH. \Vitnesses BENJAMIN B. HULL, HELEN Onrono. 

